sports Article Cardiac Autonomic and Salivary Responses to a Repeated Training Bout in Elite Swimmers Rohan Edmonds 1,†, Anthony Leicht 2,†, Brendan Burkett 1,*,† and Mark McKean 1,† 1 School of Health and Sport Sciences, University of the Sunshine Coast, Queensland 4558, Australia;
[email protected] (R.E.);
[email protected] (M.M.) 2 College of Healthcare Sciences, James Cook University, Queensland 4811, Australia;
[email protected] * Correspondence:
[email protected]; Tel.: +61-7-5430-2827; Fax: +61-7-5456-4600 † These authors contributed equally to this work. Academic Editor: Arno Schmidt-Trucksäss Received: 19 November 2015; Accepted: 18 February 2016; Published: 24 February 2016 Abstract: This study examined the acute training responses of heart rate variability (HRV) and salivary biomarkers (immunoglobulin A and alpha-amylase) following a standardised training bout in Paralympic swimmers. Changes in HRV, sIgA and sAA were documented Monday morning, Monday afternoon and Tuesday morning over a 14-week monitoring period leading into international competition. Magnitude based inferences with effect sizes (ES) were used to assess the practical significance of changes each week. Normal training responses elicited increases in HR, α1, sAA and sIgA, accompanied by decreases in HF(nu), standard deviation of instantaneous RR variability (SD1) and the root mean square of successive differences (RMSSD) from Monday morning to Monday afternoon, and to Tuesday morning with similar week to week responses for most variables. Changes in RMSSD from Monday a.m. to p.m. were likely smaller (less negative) for Week 7 (78/18/3, ES = 0.40) following a competition weekend with similar changes observed from Monday a.m.